Nowadays high strength and high performance concrete are widely used in many civil engineering constructions. To produce them it is required to reduce the water/powder ratio and increase the binder content. Superplasticizers are commonly used to achieve the workability. Silica fume is one of the popular pozzolanas used in concrete to get imporved properties. The use of silica fume in conjuction with superplastisizers has become the backbone of high strength and high performance concrete. An... Topics: high strength concrete, high performance concrete, superplastcizer, silica fumeI.